topic 2910al CDP neighbor list is empty in Switches, Hubs, and Modems

2910al CDP neighbor list is empty

Susan Lau — Tue, 04 Aug 2009 17:14:23 GMT

This is the first time we've used ProCurve switches and so far I've been successful in getting it working together with our Cisco equipment, but I'm baffled by this little problem.

I have a 2910al directly connected to a Catalyst 3560. There are no neighbors in the ProCurves CDP list, even though the 3560 is configured to send out CDP packets every 60 seconds and the ProCurve has it enabled on all ports.

Switch OS version is /sw/code/build/sbm(t4a_RC3), W.14.03

Any insights would be appreciated!

Re: 2910al CDP neighbor list is empty

Jeff Carrell — Tue, 04 Aug 2009 19:55:45 GMT

ProCurve switches respond to CDP, but cannot initiate CDP queries...that feature was removed from code a few years ago...

ProCurve instead uses the standard LLDP (link layer discovery protocol)...

cisco does support LLDP - depending on version of IOS...

i have a 3560-PS-E with 12.2(40)SE and it sees my 2626 via LLDP (sh lldp n) -and- my 2626 sees the 3560 via LLDP (sh lldp i r)...

and i just looked, my 2626 does see the 3560 via cdp as well (sh cdp n), which is a bit interesting to me...

so in the end, i can't say why your 2910 doesn't see the 3560...and i don't have a 2910 to try...

hth...jeff

Re: 2910al CDP neighbor list is empty

Susan Lau — Wed, 05 Aug 2009 12:38:06 GMT

Enabling LLDP on the Cisco switch seemed to bump it in to action. It now appears on my ProCurve's CDP neighbor list (as well as the LLDP remote-device list).

It seems odd that it would function that way, but at least it's working now.